Final answer:
The clause that protects mandating reporters from legal action is the reporter's privilege, which allows journalists to keep confidential sources anonymous.
Step-by-step explanation:
The clause that protects mandating reporters from legal action is the reporter's privilege. This privilege allows journalists to keep confidential sources anonymous in order to protect them from government prosecution.
However, it is important to note that this privilege is not absolute. In some cases, the court can force reporters to reveal their sources, such as when the government needs the source's identity for a criminal trial. An example of this can be seen in the case of Branzburg v. Hayes (1972), in which journalists were placed in contempt of court for refusing to divulge their sources.
Overall, while reporters have the privilege of protecting their sources, this privilege is not unlimited and can be called into question depending on the circumstances.